Download presentation
Presentation is loading. Please wait.
1
Motor cortical areas: the homunculus The motor system
2
Major Cortical areas involved in planning and execution of “purposeful” movements
3
Directional Tuning of MI Cells Movement onset (Georgopoulos et al 1982) P.D.
4
Set related responses in Pre-motor Cortex Prepare LEFT movementPrepare RIGHT movement
5
Mirror neurons Rizzolatti et al., 1996
6
Basic properties of the Mirror Neurons Rizzolatti et al. 1996
7
A multimodal representation of action
8
Mirror neurons in the Parietal cortex: Intention understanding?
9
Mirror neurons show the same specificity when actions are preformed by the experimenter
12
What is represented by the MN? Actions or goals? Hand unit210unit199 Umlita et al., 2008 closure opening
13
The mirror system – abstract representation of movement goals? Recordings from 37 mirror neurons in F5 in a “hidden action” paradigm 19/37 mirror neurons responded significantly in the hidden condition. 7/19 – strong responses (hidden=visual) (Umilta et al., 2001). Full vision Hidden vision
14
The mirror system in humans
15
Cortical activation during observation of mouth hand and foot action
16
Shmuelof & Zohary 2006 Viewed-Hand identity effects in parietal cortex
17
Visual and motor hand areas in the human parietal cortex
18
Specificity of visually defined “hand areas” to motor actions
19
Human mirror system Dinstein, J. Neuroscience (2008) Execute d Observe d fMRI response
20
Selectivity
21
FistHang loose Thumbs up The finger Hang loose mirror neuron The finger mirror neuron
22
Monkey mirror neurons Gallese, Brain (1996)
23
A deeper understanding of “mirror like voxels”
24
Mirror neurons should show cross-modal adaptation Mirror regions should be active both during viewing action and motor action
25
Adaptation First presentation Repeated presentation
26
Movement selective adaptation RepeatsNon-repeats
27
Visual adaptation Observe RepeatsNon-repeats
28
Motor adaptation Execute RepeatsNon-repeats
29
Cross-modal adaptation ExecuteObserveExecuteObserve RepeatsNon-repeats
30
Cross-modal adaptation ObserveExecuteObserveExecute RepeatsNon-repeats
31
Rock paper scissors Dinstein 2008 Get extra $10 if you win more than you lose!
32
Game Timeline Observe Time
33
Execute Time Game Timeline Observe
34
RepeatNon-repeat Execute Time Game Timeline Observe
35
RepeatNon-repeat Execute Time Game Timeline Observe
36
RepeatNon-repeat Execute Time Game Timeline Observe
37
RepeatNon-repeat Execute Time Game Timeline Observe
38
RepeatNon-repeat Execute Time Game Timeline Observe
39
RepeatNon-repeat Execute Time Game Timeline
40
Visual adaptation Green: observed non-repeat > repeat Mirror system areas
41
Motor adaptation Purple: executed non-repeat > repeat Mirror system areas
42
Motor & visual adaptation Yellow: overlap of motor and visual adaptation Mirror system areas
43
Motor & visual adaptation Yellow: overlap of motor and visual adaptation No cross modal adaptation Mirror system areas
44
ROI Analysis
45
Adaptation summary 1.Selectivity for movements in “Mirror system” areas. 2.Adaptation may be taking place in a single population of mirror neurons and/or in two separate populations of visual and motor neurons adapting independently. 3.We now have a way of studying movement selective responses; the critical feature of neural populations involved in movement perception. Dinstein J. Neurophysiology 2007
46
Classification Typical mirror region = ~ 300 voxels ExecutedObserved fMRI response
47
Classification Executed fMRI response No specificity in the overall fMRI signal (across voxels)
48
Classification Specificity in the fMRI signal (within voxels)
49
Movement selective patterns StrongWeak Activation level
50
Are patterns distinct & reproducible? Trial #1 …. Execute Trial #2 Trial #3 Trial #4
51
Are patterns distinct & reproducible? Trial #1 …. Observe Trial #2 Trial #3 Trial #4
52
Classify movement patterns Decoding accuracy R P S Execute d Observe d R P S Primary motor & somatosensory
53
Classify movement patterns Decoding accuracy R P S Execute d Observe d R P S Early visual areas
54
Classify movement patterns Decoding accuracy R P S Execute d Observe d R P S Ventral premotor
55
Classify movement patterns Decoding accuracy LeftRight R P S Execute d Observe d Execute d Observe d Anterior intraparietal sulcus
56
Different patterns across modalities Executed to observed Observed to executed R P S Left aIPSRight aIPS
57
Execute Different patterns across modalities Observe
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.